engine JEEP WRANGLER 2008 JK / 3.G Workshop Manual

branches or other obstacles on the path? Can you safely
recover the vehicle if something goes wrong? If every-
thing looks good and you feel confident, shift the trans-
mission into a lower gear with 4L (Low) engaged, and
proceed with caution maintaining your momentum as
you climb the hill.
Driving Up Hill
Once you have determined your ability to proceed and
have shifted into the appropriate gear, line your vehicle
up for the straightest possible run. Accelerate with an
easy constant throttle and apply more power as you start
up the hill. Do not race forward into a steep grade, the
abrupt change of grade could cause you to lose control. If
the front end begins to bounce, ease off the throttle
slightly to bring all four tires back on the ground. As you
approach the crest of the hill, ease off the throttle and
slowly proceed over the top. If the wheels start to slip as
you approach the crest of a hill, ease off the accelerator
and maintain headway by turning the steering wheel nomore than a 1/4 turn quickly back and forth. This will
provide a fresh
biteinto the surface and will usually
provide enough traction to complete the climb. If you do
not make it to the top, place the vehicle in REVERSE and
back straight down the grade using engine resistance
along with the vehicle brakes.WARNING!
Never attempt to climb a hill at an angle or turn
around on a steep grade. Driving across an incline
increases the risk of a rollover, which may result in
severe injury.
Driving Down Hill
Before driving down a steep hill you need to determine if
it is too steep for a safe descent. What is the surface
traction? Is the grade too steep to maintain a slow
controlled descent? Are there obstacles? Is it a straight
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descent? Is there plenty of distance at the base of the hill
to regain control if the vehicle descends to fast? If you feel
confident in your ability to proceed then make sure you
are in 4L (Low) and proceed with caution. Allow engine
braking to control the descent and apply your brakes if
necessary, but do not allow the tires to lock.
WARNING!
Do not descend a steep grade in NEUTRAL. Use
vehicle brakes in conjunction with engine braking.
Descending a grade too fast could cause you to lose
control and be seriously injured.
Driving Across An Incline
If at all possible avoid driving across an incline. If it is
necessary, know your vehicle’s abilities. Driving across
an incline places more weight on the downhill wheels,
which increases the possibilities of a downhill slide orrollover. Make sure the surface has good traction with
firm and stable soils. If possible transverse the incline at
an angle heading slightly up or down.
WARNING!
Driving across an incline increases the risk of a
rollover, which may result in severe injury.
If You Stall Or Begin To Lose Headway
If you stall or begin to lose headway while climbing a
steep hill, allow your vehicle to come to a stop and
immediately apply the brake. Restart the engine and shift
into REVERSE. Back slowly down the hill allowing
engine braking to control the descent and apply your
brakes if necessary, but do not allow the tires to lock.
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WARNING!
If the engine stalls or you lose headway or cannot
make it to the top of a steep hill or grade, never
attempt to turn around. To do so may result in
tipping and rolling the vehicle, which may result in
severe injury. Always back carefully straight down a
hill in REVERSE gear. Never back down a hill in
NEUTRAL using only the vehicle brakes. Never
drive diagonally across a hill, always drive straight
up or down.
Driving Through Water
Extreme care should be taken crossing any type of water.
Water crossings should be avoided if possible, and only
be attempted when necessary in a safe responsible man-
ner. You should only drive through areas which are
designated and approved. You should tread lightly andavoid damage to the environment. You should know
your vehicles abilities and be able to recover it if some-
thing goes wrong. You should never stop or shut a
vehicle off when crossing deep water unless you ingested
water into the engine air intake. If the engine stalls, do
not attempt to restart it. Determine if it has ingested
water first. The key to any crossing is low and slow. Shift
into 1st gear (manual transmission), or DRIVE (automatic
transmission), with the transfer case in the 4L (Low)
position and proceed very slowly with a constant slow
speed {3 to 5 mph (5 to 8 km/h) maximum} and light
throttle. Keep the vehicle moving; do not try to accelerate
through the crossing. After crossing any water higher
than the bottom of the axle differentials, you should
inspect all of the vehicle fluids for signs of water inges-
tion.
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CAUTION!
Water ingestion into the axles, transmission, transfer
case, engine or vehicle interior can occur if you drive
too fast or through too deep of water. Water can cause
permanent damage to engine, driveline or other
vehicle components and your brakes will be less
effective once wet and/or muddy.
Before You Cross Any Type Of Water
As you approach any type of water you need to deter-
mine if you can cross it safely and responsibly. If neces-
sary, get out and walk through the water or probe it with
a stick. You need to be sure of its depth, approach angle,
current and bottom condition. Be careful of murky or
muddy waters, check for hidden obstacles. Make sure
you will not be intruding on any wildlife and you can
recover the vehicle if necessary. The key to a safe crossingis the water depth, current and bottom conditions. On
soft bottoms the vehicle will sink in, effectively increas-
ing the water level on the vehicle. Be sure to consider this
when determining the depth and the ability to safely
cross
Crossing Puddles, Pools, Flooded Areas Or Other
Standing Water
Puddles, pools, flooded or other standing water areas
normally contain murky or muddy waters. These water
types normally contain hidden obstacles and make it
difficult to determine an accurate water depth, approach
angle, and bottom condition. Murky or muddy water
holes are where you want to hook up tow straps prior to
entering. This makes for a faster, cleaner and easier
vehicle recovery. If you are able to determine you can
safely cross, than proceed using the low and slow
method.
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FUEL REQUIREMENTS
All engines (except 5.7L engines) are de-
signed to meet all emissions regulations
and provide excellent fuel economy and
performance when using high quality un-
leaded “regular” gasoline having an oc-
tane rating of 87. The use of premium
gasoline is not recommended. Under normal conditions,
the use of premium gasoline will not provide a benefit
over high quality regular gasoline, and in some circum-
stances may result in poorer performance.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required. Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of gasoline before consid-
ering service for the vehicle.
Over 40 auto manufacturer’s worldwide have issued and
endorsed consistent gasoline specifications (the World-
wide Fuel Charter, WWFC) to define fuel properties
necessary to deliver enhanced emissions, performance,
and durability for your vehicle. The manufacturer recom-
mends the use of gasoline that meets the WWFC speci-
fications if they are available.
Reformulated Gasoline
Many areas of the country require the use of cleaner
burning gasoline referred to as “Reformulated Gasoline.”
Reformulated gasoline contains oxygenates, and are spe-
cifically blended to reduce vehicle emissions and im-
prove air quality.
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The manufacturer supports the use of reformulated gaso-
line. Properly blended reformulated gasoline will pro-
vide excellent performance and durability for the engine
and fuel system components.
Gasoline/Oxygenate Blends
Some fuel suppliers blend unleaded gasoline with oxy-
genates such as 10% ethanol, MTBE, and ETBE. Oxygen-
ates are required in some areas of the country during the
winter months to reduce carbon monoxide emissions.
Fuels blended with these oxygenates may be used in
your vehicle.
CAUTION!
DO NOT use gasolines containing Methanol. Use of
these blends may result in starting and drivability
problems and may damage critical fuel system
components.Problems that result from using methanol/gasoline
blends are not the responsibility of the manufacturer.
While MTBE is an oxygenate made from Methanol, it
does not have the negative effects of Methanol.
MMT In Gasoline
MMT is a manganese containing metallic additive that is
blended into some gasoline to increase the octane num-
ber. Gasoline blended with MMT offers no performance
advantage beyond gasoline of the same octane number
without MMT. Gasoline blended with MMT has shown
to reduce sparkplug life and reduce emission system
performance in some vehicles. The manufacturer recom-
mends that gasoline without MMT be used in your
vehicle. The MMT content of gasoline may not be indi-
cated on the gasoline pump, therefore, you should ask
your gasoline retailer if the gasoline contains MMT.
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It is even more important to look for gasoline without
MMT in Canada, because MMT can be used at levels
higher than those allowed in the United States.
MMT is prohibited in Federal and California-
reformulated gasoline.
Materials Added To Fuel
All gasoline sold in the United States is required to
contain effective detergent additives. Use of additional
detergents or other additives are not needed under
normal conditions and would result in additional cost.
Therefore you should not have to add anything to the
fuel.
Fuel System Cautions
CAUTION!
Follow these guidelines to maintain your vehicle’s
performance:
•The use of leaded gasoline is prohibited by Federal
law. Using leaded gasoline can impair engine perfor-
mance, and damage the emission control system.
•An out-of-tune engine, or certain fuel or ignition
malfunctions, can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact your authorized dealer for service assistance.
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•The use of fuel additives which are now being sold as
octane enhancers is not recommended. Most of these
products contain high concentrations of methanol.
Fuel system damage or vehicle performance problems
resulting from the use of such fuels or additives is not
the responsibility of the manufacturer.
NOTE: Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
Carbon Monoxide Warnings
WARNING!
Carbon monoxide (CO) in exhaust gases is deadly.
Follow the precautions below to prevent carbon
monoxide poisoning:
•Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas which can kill.
Never run the engine in a closed area, such as a
garage, and never sit in a parked vehicle with the
engine running for an extended period. If the vehicle is
stopped in an open area with the engine running for
more than a short period, adjust the ventilation system
to force fresh, outside air into the vehicle.
•Guard against carbon monoxide with proper mainte-
nance. Have the exhaust system inspected every time
the vehicle is raised. Have any abnormal conditions
repaired promptly. Until repaired, drive with all side
windows fully open.
•Keep the swing gate closed when driving your vehicle
to prevent carbon monoxide and other poisonous
exhaust gases from entering the vehicle.
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CAUTION!
Damage to the fuel system or emission control sys-
tem could result from using an improper fuel cap
(gas cap). A poorly fitting cap could let impurities
into the fuel system. Also, a poorly fitting after-
market cap can cause the Malfunction Indicator Light
to illuminate, due to fuel vapors escaping from the
system.
CAUTION!
To avoid fuel spillage and overfilling, do not “top
off” the fuel tank after filling.
NOTE: When the fuel nozzle “clicks” or shuts off, the
fuel tank is full.
WARNING!
•Never have any smoking materials lit in or near
the vehicle when the gas cap is removed or the
tank filled.
•Never add fuel when the engine is running. This is
in violation of most state and federal fire regula-
tions and will cause the Malfunction Indicator
Light to turn on.
NOTE: Tighten the gas cap about 1/4 turn until you
hear one click. This is an indication that cap is properly
tightened.
If the gas cap is not tightened properly, the Malfunction
Indicator Light will come on. Be sure the gas cap is
tightened every time the vehicle is refueled.
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Engine/
Transmission Axle Model GCWR (Gross
Combined Wt.Rating) Frontal Area Max. GTW
(Gross TrailerWt.) Max. Trailer
Tongue Wt. (See Note)
3.8L/Manual 3.21 2–Door X Model (4WD)4,987 lbs
(2 262 kg) 25 sq ft
(2.32 sq m) 1,000 lbs
(453 kg) 100 lbs (45 kg)
3.8L/Manual 3.73 2–Door X Model (4WD)5,987 lbs
(2 716 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/
Automatic 3.73 2–Door X
Model (4WD) 6,032 lbs
(2 736 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/Manual 3.21 2–Door Sahara Model (4WD)5,163 lbs
(2 342 kg) 25 sq ft
(2.32 sq m) 1,000 lbs
(453 kg) 100 lbs (45 kg)
3.8L/Manual 3.73 2–Door Sahara Model (4WD)6,163 lbs
(2 795 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/
Automatic 3.73 2–Door Sahara
Model (4WD) 6,163 lbs
(2 795 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/Manual 4.10 2–Door Rubi- con Model(4WD) 6,236 lbs
(2 829 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
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